Electrical connector



Feb. l, 1966 l.. G. FIALA 3,233,206

ELECTRICAL CONNECTOR Filed May 3l, 1965 2 Sheets-Sheet 1 F151 J0 MZ 4/0 y A/L///////// l www' 65 Feb. l, 1966 L. G. FIALA 3,233,206

ELECTRICAL CONNECTOR Filed May 3l, 1965 2 Sheets-Sheet 2 FHE q FIE7 United States Patent O 3,233,206 ELECTRICAL CONNECTOR Lee G. Fiala, Chicago, Ill., assignor of ten percent to Joseph N. Sicuro, ten percent to Robert McLean, and ten percent to `lames L. Lutiger Filed May 31, 1963, Ser. No. 284,466 7 Claims. (Cl. 339-498) The present invention relates to solderless connectors for electrically interconnecting insulated wires without the necessity of manually stripping the insulation therefrom.

In the older forms of solderless connectors, it was necessary to manually strip the insulation from the wires to be joined before the wires could be connected. A large area of contact between the wires themselves or between the wires and their intermediate connector resulted, but the job of removing one or more layers of insulation proved to be a time consuming and costly job. In more recent connectors, the insulation was pierced by connector prongs in the process of assembling the wires to the connector. Another form of connector utilized mating jaws which were aligned on either side of the wires being connected resulting in line contact at diametric sides of the wire conductor. In this way, the necessity of stripping away the insulation was elimi nated but the resulting area of contact was small and resulted in high resistance contact between the Wires. Thus, if a large area of contact was required to insure efcient low resistance connection of the wires, the insulation had to be removed before the wires could be assembled into the connector. If the insulation was not removed prior Vto the placement of the wires in the connector, the user had to be content with small areas of contact and the resulting high resistance connection.

It is therefore an object of the invention to provide an improved solderless connector which does not require the removal of the insulation before assembly, yet which provides a large area of contact between the wires and the interconnecting conductor.

To provide this and other objects, the invention comprises a folded sheet metal connector which has a vertical stationary wall with channels slotted in its upper edge. These channels each extend mutually parallel, and spaced apart with tapering, converging sharp planar edges terminating in individual arcuate wire receiving edges. A second wall is hinged to close on said first wall toward a position parallel to and closely adjacent the stationary wall. The second wall has spaced channels spaced apart a distance like that of the stationary wall channels. On closure of said second wall, the arcuate edges of the channels on said walls confront one another to form bores about the wires received therein. On complete closure of sai-d second wall, said bores completely sever the insulation on the respective wires.

An insulating housing is tted over the connector and the wires are grasped and tugged once firmly to strip the wires bare for a section adjacent the bores. The housing cavity has a tapered wall which forces locking arm of the connector against the stripped section to depress the stripped section against the adjacent connector wall. The housing is then covered by a cap which exerts further pressure on the locking arm to maintain the stripped section firmly in contact with the adjacent connector wall in permanent fashion. Thus, a large area of contact betweenthe wires and the connector is effected in an assembly process which eliminates the necessity of manually stripping the wires prior to assembly in the connector.

These and other objects and features will be apparent from the following detailed description viewed with the accompanying drawings in which:

FIGURE l is a plan view in elevation of a complete connector assembly embodying the present invention, the exterior housing of which is partially broken away to expose the conducting connector;

FIGURE 2 is a front elevational view of the connector assembly of FIGURE 1 with the front insulating cap removed;

FIGURE 3 is a sectional view taken along line 3 3 of FIGURE 2;

FIGURE 4 is a front elevational View of a conducting connector removed from its housing and opened to its wire receiving position for the start of the assembly process;

FIGURE 5 is a sectional view taken along line 5-5 of FIGURE 4;

FIGURE 6 is a sectional view taken along line 6 6 of FIGURE 4;

FIGURE 7 is a rear view in elevation of the of FIGURE 1;

FIGURE 8 is a front elevational view of the connector of FIGURE 4 in its partially closed position during the assembly process;

FIGURE 9 is a sectional View taken along line 9-9 of FIGURE 8;

FIGURE 10 is an elevational view of the insulating cap of FIGURE l removed from the housing and viewed from the rear or interior side; and

FIGURE l1 is an elevational view of connector.

Turning now to the gures in detail, in FIGURE 1 there is shown a completely enclosed connector assembly including an outer housing 10, generally rectangular in cross-section, which is fabricated of insulating material which may be of any suitable plastic, such as polyethylene. This housing 10 has a-n open front end 12 which is covered by an insulating cap 14, also of polyethylene, which is in the form of a rectangular plate. The cap 14 has a rearwardly extending flange 16 about its perimeter, the flange terminating in an inwardly directed ridge 20 extending continuously about the flange. This ridge 'is adapted to snap t into a groove 22 cut into the side, top and bottom walls of housing 10 parallel to the front opening 12. The ridge 20, by virtue of the inherent resilience of the cap material, yields sufficiently to slide into the groove 22 and resiliently locks the cap 14 onto the housing.

The housing rear wall 24 has a rectangular passage 26 leading from its inner cavity 2.8 to the exterior. Passage 26 is sufficiently large to accommodate the two` insulated single conductor wires 30 and 32 which are joined or connected in the connector assembly. The wires 30 an-d 32 extend through the passage 26 in side-by-side arrangement into the housing cavity 28 for connection in the conducting connector 460. The cavity 28 has five flat surfaces or walls within the housing 10, designated 41, 42, 43, 44 and 45. The rear surface 44 is disposed normal to the opposed parallel side surfaces 41 and 43. The top interior housing surface 42 is inclined downwardly at a slightly obtuse angle towards a line of joinder to rear surface 44 of the cavity. The cavity bottom wall 45 also is inclined slightly upwardly toward the rear wall, thus forming a cavity with a smaller cross section remote from the opening 12 than adjacent the opening 12. It should be noted that the front cap 14 has three spaced, inwardly directed projections or embosses 46 which abut against and push on the front Wall 4S of the base 50 of connector 40, as will be more fully explained hereafter.

The connector is constructed of suitable conducting sheet metal of llight gauge to provide a degree of inherent resilience in the connector. The connector 40 is a unitary structure comprising a base 50 and a cover 52 both hinged together by a sidewall 54 as will be explained. In FIG- assembly of a modified form disposed at anvan'gle to the fron-t wall 48 equal to the supplement of the angle between the surafecs 44 and 45 ofthecavityrZS. 'Extending' from the edge of the oor 56 is double-acting sidewall hinge 54 which connects the Vcover 52 to`thebase"50. This hinge vhasa bend 55 :'centrally'thereof along a line fvparallelto the oor 56 -to `vhinge ..the cover Ato..-the1.base in Va Tmanner, allowing sideway movement of cover 52 for alignment with the base has a sidewall 58 extending normally from the floor 156" to aboutv the height: ofr thefront'wall 48 and its rearward dimension matches that of the oor 56 to form fthe 1 generally rectangular: coniiguration of the' connector.

The connector is dimensionally designed for a slight interr'ference yfit within'the housing-cavityZS to firmly position and lock the` connectorrttherein.

Cover 52 has a flat top wall 60 which extends from ...the vendof the'hinge. 54. This top wall 60 has a bend 6-1 slightly greater than a right angle and a section integrally form-ing a'front wall 62 disposed parallel to 1` ther-base `front `walli48. Top fw-all 60 .has a rearward bend 63 parallel to the bend 61 forming an elbow-shaped :locking brace :64. Thebrace 64 has a bend 65 parallel to the bends 61 and 63 which forms section 66 extending rearwardly ofthe end of top wall 66, and a second section68 which termina-tes in a transversely extending edge 72 adjacent the rea-r surface 74 `of cover front wall 62 and `parallelrfto `the bends 61, 6-3`and 65. Edge 72 has a lengthabout equal to 'they transversev dimension of front vv'wall 48. -A sidewall 76 is formed by a bend 77 normal to 'the bend 61 at the end remoteffromthe front hinge Y'4'to complete the generally rectangular structure of the cover'52.

Inthebasefront wall 48, as viewed in FIGURE 4, there `a're twofspacedfapart, parallel U-shaped channels 80 slotted into the top surface82 of the front wall. These channelsare each formed byl sloping edges 83 which converge uniformly' from their top opening 84 in surface -8'2'to` terminate in an arcuate edge A86 slightly below the mid level'zof the'front wall. The arcuate edges 86 of the front wall 48 and the straight edges 83 of these channels 80 arebeveled or otherwise .sharpened to produce channel edges which will cut through wire insulation.

Similarchannels 90'areslotted into front wall 62 of :the ycover 52 with inwardly sloped edges 92 convergingly extending from top opening' 94 in the front Wall 62 to termination at an .arcuateedge 96. These channels 90 are spacedl apart a distance equal to the distance between the base channelsV 80, are alignable therewith on closure vof the cover 52 on bending of` hinge sidewall 54, and

lhave their straight edges 92 and arcuate edges 96 beveled or sharpened as previously mentioned for channels 80.

The channels 80 are configuredk so that when wires 30 and 32 are placed individually in the channels, the insulation 100 of the wires restsnear the top'open end 84, and when the wires are depressed into channels Sti,

the straight edgesSS cut into the insulation. The converging shape of the straight edges 83 tends to cut the insulation more as the wires are depressed toward arcuate 1 edges 86. The acrossthechannel dimension adjacent the arcuate edge 86 in each channel 80 is slightly smaller than the diameter of the circular cross section of the wire conductor 102 :with the insulation 100 slit through. This dimensioning insu-res that'the insulation layer will be' fully cut through when the conductor rests on arcuate edge 86. In this position, the outer surface of the `wire conductor 102 may be slightly scored but not suiciently t-o impair the wire strength.

Channels 90 as shown are similar in shape, size and positioning to channels for reasons which will become apparent as the assembly of wires into the connector assembly is explained.- Further, it will be seen that each connector has channels dimensioned for a particular gauge wire for optimum ease of assembly.

To assemble wires 30v and'32 ina connector assembly, the first step includesthreading the wire through wire passage 26 in the housing rear wall and thereafter passing these wires through the open front end 12 of the housing f10. The housing may 'be held in any suitable way on the wires away from the wire ends to facilitate the connector assembly process.

A connector 40 is then held securely and individual wires 30 and'32 are positioned into individual channels each cover the top half of the wirest) and 32v resting inthe base channels-80.

The cover 52 is Vthen further depressed onto kbase 50 and the sharpened straight edges l92 and arcuate edges 96 cut into the wire `insulation 100 and force the wires ydownwardly onto sharpened straight edges 83 `and sharpened arcuate edges 86,: as bestillustrated in FIGURES.

As the cover is further depressed downwardly, the channel edges cut through the insulation until the insulation is completely cut through by vthecooperative cutting action of the base channel edges and cover channel edges. f When the insulation is completely cut through, each conductor 192 is abutting arcuate edges 86 and 96vand at that time, the top wall 60 isV parallel and closely adjacent totop surface 82 of the front wall'48 of the base 5t). The upper and lower arcuate edges 86 and 96 combinedly form circular bores in abutment with the wire conductors with the insulation cut through oircularly.

During this closure ofthe cover 52 onto the base 50 and consequent cutting through of the insulation, free edge-72 of thef cantilevered section 68 of lock brace 64 is in abutment with the insulation layer of the wi-res 30 -and'32 closely adjacent the rear surface of base front `wall 43. The 'wires Stland 32, however, are 'free to Y sharply to bare or strip a section of the wires at the rear of the channelbores including scraping all nonco-nductive material from the entire area of the bared wire. As the housing 10 is forcibly advanced onto the connect-or, the cut lin the insulation is lengthened, and the sloped interior top wall 42 and bottom wall 45 of the cavity successively depress the co-ver- SF2 to its fullclosed position over base Sti. Also, the bend line 65 is forced into abutment with the rear surface 44 of the rear wall 24 of the housing, and pressure is generated by the bracefree edge 72 on the wires adjacent the cut in insulation. As the housing 10 is further drawn Von the connector 40, the free edge 72 is wedged against the stripped portions of both wires 30 and 32 being forced into contact with the edge 72 of the electrically conducting connector 40 and the floor 56 thereof.

This vassernblyris completed by placing the cap 14 on the housing open front end and compressing the cap onto the front edge of the housing perimeter until ridge 20 reaches and mates with the cooperating grooves 22. aboutt the housing perimeter adjacent to the front opening 12. The connector 40 is secured in position by the three spaced bosses 46 which protrude reapwardly from the cap 14 into a compressive abutment with the front wall 62 of the cover 52 on either side of the wires 30 and 3.2. The compressive force generated by these bosses holds the connector 40 tightly against the cavity rear wall 44 and maintains the tight electrical connection of the wires 30 and 32 to the connector 40. The spaces between these projections 46 serve to contain the exposed portions of the wires 30 and 32 forward of the connector 40 and the wires must be cut to fit within this volume before mounting the cap 14 on the housing 10.

As a result of this construction, a large area of contact between the wires 30 and 32 `and the connector 40 is provided, in that three separate regions of contact to each wire are provided, namely: first, line contact between the wi-re conductors 30 and 32 and the channel edges 86 and 96; second, surface contact between the edge 72 of the brace '64 and the conductors; vand thi-rd, surface .contact Ibetween the stripped conductors and the floor 56 and front Wall `48 of the base. The insulation -is cut through by the assembly process and the entire assembly is fully insulated by the protective outer housing 10.

In the emb-odiment of the invention shown in FIGURE 10, the modified connector 40a is identical to connector 40 except that the shape of the channels 80a in the front wall of base 50a and channels 90a in the front wall of cover 52a have been modified t-o what may be termed the key hole shape shown. The positioning, relative size and number lof the channels have not been changed in this modification.

In describing the key hole shape, one of the channels 89a will be described with the understanding that the re- -maining channels are shaped accordingly. In channel 80a, the channel walls 110 angle sharply in a converging direc-tion from the open edge 111 of the channel. These converging Walls are edged by beveling or other similar means and reach aligned shoulders 112 on either .side of the channel opening. From the shoulders, the edged Walls 110 extend into a circular section 114, the diameter of which is greater than the distance across the channel between confronting shoulders. This circular section 114 forms -the bottom of the channel or arcuate edges on which the wire conductor rests at the conclusion of the assembly process.

In assembly, the wires 30 and 32 are placed individually in respective lower channels 80a, and will rest in the channels above the confronting shoulders 112. The cove-r 52a is pivot-ed and channels 90a are aligned with channels 80a and the cover is further closed. Shoulders in the upper channels 96a depress the wires past shoulders 80a cutting through the side insulati-on. The cover 52a is further depressed forcing the wires onto bottom arcuate edges 114 cutting through the bottom insulation on the wires and arcuate edges of upper channels 90a complete the severing of the insulation in a single annular cut on each wire. The cir-cular section of both upper vand lower channels cooperatively form a bore :slightly larger in diameter than the diameter of the wire conduct-or but the narrowest portion of the channel 80 in t-he region of the shoulders 112 is slightly less than the diameter of the wire to insure lthat the insulation Will 'be completely severed in the assembly process.

The remaining assembly steps are identical to that previously described, except that the shoulders 112 act to hold the insulation against movement when the wires are tugged sharply to bare a section of the wire conductors to produce a large contact area in the completed assembly.

It is to be noted that the present invention lmay be used to interconnect stranded wires as well as solid core wires. Also, more than two wires may be interconnected in a single wire lock by providing the necessary number of separate channels 80 and 90 for each wire.

From the foregoing dis-closure, those skilled in the art will devise many applications, modifications .and improvements within the intended scope of this invention. It is therefore inten-ded that the scope of this invention be not limited by the foregoing disclosure, -but rather only `by the appended claims.

The invention claimed is:

1. A connector for electrical-ly connecting insulated wires, comprising an electrical-ly conducting base, :a plurality of individual wire receiving channels in said base, edged walls in said channels for cutting through the insulation of wires placed in said base channels, a cover including a plurality of channels aligned with the channels in said base, said cover channel Walls being edged to score and cut through the insulation of wires in said base channels on closure of said cover on said base, sa-id base channel walls `and said cover channel walls cooperating to sever t-he insulation about said wires on the closure of said cover on said base, an arm extending from said connector into contact With the wires adjacent the channels on the closure of said cover, an insulating hou-sing litt-ing about said connector, said housing having walls positioned t-o act on said arm and force said arm against the wires adjacent the severed insulation to compress said wires into contact with the electrically conducting walls of said base, and means for restraining said wires in said position.

2. An electric-al connect-or for joining a plurality of insulated wires into electrical contact comprising, a first conducting wall with a plurality of open-topped, edged wire receiving slots, a seco-nd conducting wall parallel and closely adjacent to said Vfirst wall, said second wall including a like plurality `of slots aligned with the slots in the first wall and inverted with respect thereto to form a plurality of wire receiving bores extending through `both said walls, said bores each having a diameter .slightly smaller than the diameter of the individual conductors of the respective wires received in each of said bores, edged walls in each of said bores adapted to cut through the insulation about wire conductors on closure lof said second wall into the bore forming position and for unsheathing `a section of said insulation adjacent said walls on movement of said wires normal to said bores, a further conductive w-all angled from one of said walls and in electrical contact with said one wall, said furt-her wall contacting said wires along said unsheathed section to compress said unsheathed sections against the adjacent front Wall to complete -a compressive electrical contact between the wire .conduct-ors and said adjacent wall, and means for further compressing said further wall against said wires and maintaining said compressive contact permanently.

3. A connector for completing permanent electrica-l connection between insulated wires comprising a sheet metal base including a front wall and a bott-om Wall substantially rectangularly disposed from said front wall, channels cut into said front wall, each channel having an open top end and edged tapering sidewalls terminating at an arcuate edged lower surface, the across-the-channel dimension adjacent the arcuate bottom of each of said channels being of slightly lesser dimension than the diameter of the conductor of the respective wires placed into each of said channels, a sheet metal cover adapted to fit over said base, `said cover including a front wall and a top wall, a wall hinging said cover to said base for pivotal motion .in a plante parallel to said base front wall to align said front wall of the cover adjacent the front wall of the base, channels in the front wall of the cover alignable with the channels in said base, said cover channels including edged walls shaped similarly to the channel walls of said base, said channel walls cooperatively positioned to completely sever the insulation on said wires on the closure of :said cover onto said base, an arm extending from the rear iend of the top wall to contact the wires adjacent the severed insulation near the front wall of said base, an insulating housing iitting over said closed cover and said base, said housing including an open front end receptive of essence the closed cover and base, and a rearwardly tapering cavity in said housing depressive of said arm `on said housing being drawn over said base and cover to force said arm and the wires adjacent the bottom wall of the base.

and into electrical contact With the front wall and the bottom wall of the base.

4. A connector providing an electrical connection between a first and a second insulated wire, said connector including an electrically conducting lower structure,V a iirst and a second parallel spaced channels slotted in said lower structure and having sharply edged walls extending from a top opening for receiving individual wires therein to a bottom arcuate edged surface, an upper structure hinged to said lower structure for movement with respect to said lower stru-cture, said upper structure including a `rst and a second channel, each of the channels of the upper structure having an open end from which edged walls converge to an arcuate bottom wall, said upper structure movable into a covering relation to said lower structure wherein said first channel in a said upper structure confronts said first channel in said lower structure to cooperatively therewith form an oval shape enclosing the wire placed in said first channel of said lower structure, said upper structure movable further onto said lower structure to place said second channels into similar confronting relation about a wire in the second channel of the lower structure, said edged Walls on said further lmovement cutting into the insulation in the wires in said channels, the channels in a final fully closed position of said upper 4structure each describing a circular opening about each of said wires of slightly smaller diameter than the diameter or the insulation onsaid wires to there- 'by fully cut through the insulation in said wires, means on said connector for scraping back a length of insulation `from the fully cut through insulation and means forcing said wires under said scraped back insulation into contact with the connector and locking said wires in contact with :said connector.

5. A connectorfor electrically interconnecting a first and a second insulated wire, including a metallic structure comprising a first vertical wall, a horizontal supporting Wall jointed to said vertical wall at the bottom edge thereof, a first and a second parallel spaced-apart wire receiving -channel in said vertical wall, said channels each having an open top and -side edges which converge from said open top t-o terminate in an arcuate bottom edge, said channel edges beveled to cut into the insulation of first and second wires placed respectively in said first and second channels, a second vertical wall, means hinging said second vertical wall to :said horizontal wall for vmovement in a plane parallel to said first vertical wall, said second vertical wall including a first and a second channel similar in shape and spacing to the channels in said first vertical wall, a horizontal cover wall extending from the edge of said second vertical wall opposite the open tops of the channels in said second vertical wall, said horizontal cover wall movable with said second vertical Wall on movement thereof, said second vertical wall on movement about said hinge means pivot-al to a position closely adjacent said first vert-i-cal wall with the first and second channels in said second vertical wall inverted and confronting the respective first and second channels in said first wall to enclose within said confronting channels the respective first and second insulated wires, said second wall further movable with respect to said first Wall Whereby said channel edges cooperatively act on the insulation of said wires to cut said insulation toward a nal position wherein said first and second vertical walls are in mutual alignment and said confronting channels forni individual bores about the first and second wires, the bores about e-ach of said wires of diameter slightly smaller than the diameter of the respective conductors of the wires within said bores to completely sever the insulation about lili :said wire conductors in said circular bores, an obliquely disposed wall extending fromsaid cover wall from the :edge opposite the joinder of the -cover wall to the second vertical wall, said oblique wall positioned to commonly contact the first and second wires adjacent the severedY in- V:sulation, saidl channel 'bores sized to hold the insulation -on `the opposed side of the vertical. walls on movement of 'the wires in the direction toward the oblique wall to thereby strip bare a section of insulation on each of said wires, an insulating housing fitting over said metallic structure, inclined walls in said housing. depressive of said oblique wall on movement of said housing toward :said vertical wallsto a lfinal position in which said hous- :ing encloses said structure, said oblique wall responsive :to the housing reaching said final posit-ion for compress- ,ing said stripped wire sections against a vertical wall and :against the horizontal supporting wall and in electrical rcontact therewith, and cap means engageable with said housing for increasing the compressive force on said oblique wall andV on said conductors to lock said elec- ,trical contact.

d. A connector for making electrical contact with an insulated wire comprising an electrically conducting base, :a wire receiving channel disposedV in said base, said channel having edged w-alls for cutting through the-insulation of a wire placed' in said base channel, a cover including :a channel aligned with the channel in the base, said'cover channel having walls edged to score and, cut through the insulation of -a wirein said base channel on closure of said cover on said base, said base channel walls and said cover channel walls cooperating to sever the insulation about said wire on the closure of said cover on` said base, 4an arm extending from said connector into contact with a wire disposed in said channels enclosure of said cover, :and means operatively associated with the connector to act fon said arm and force said arm against the wire disposed in the channels adjacent t-o the severed insulation to compress said wire into contact with` the electrically conducting walls of said base.

7. A connector ior` electrically connecting insulated 'wires comprising an electrically conducting base, a plurality of individual wire receiving channels in said base, said channels having edged walls for cutting through the insulation of wires placed in said base channels, a cover including a plurality of channels aligned with the channels in the base, said cover channel Walls being edged to :score and cut through the insulation of wires in said channels -on cl-osure of saidcover on said base, said'base channel walls and said cover channel Walls cooperating to :sever t-he insulation about said wires on the closure of said cover on said base, an .arm extending from the cover into contact with the wires adjacent to the channels on closure of said cover, and means acting on said arm to force said arm. against the wires .adjacent to the severed insulation to compress and maintain said wires intoconta-ct with the electrically conducting wal-ls of saidbase.

References Cited bythe Examiner UNITED STATES PATENTS 2,476,227 7/ 1949 Seller 339-95 2,534,881 12/195() Schroeder 174-84 2,685,720 8/1954 Petri 24-73 3,117,829 l/l964 Leach 339-97 3,118,715 1/1964 Potruc-h 339-98 3,168,615 2 /1965 Owen et al. 339-98 X FOREIGN PATENTS 615,737 l/l949 Great Britain.

JOSEPH D. SEERS, Primary Examiner.

W. DONALD MILLER, Examiner. 

1. A CONNECTOR FOR ELECTRICALLY CONNECTING INSULATED WIRES, COMPRISING AN ELECTRICALLY CONDUCTING BASE, A PLURALITY OF INDIVIDUAL WIRE RECEIVING CHANNELS IN SAID BASE, EDGED WALLS IN SAID CHANNELS FOR CUTTING THROUGH THE INSULATION OF WIRES PLACED IN SAID BASE CHANNELS, A COVER INCLUDING A PLURALITY OF CHANNELS ALIGNED WITH THE CHANNELS IN SAID BASE, SAID COVER CHANNEL WALLS BEING EDGED TO SCORE AND CUT THROUGH THE INSULATION OF WIRES IN SAID BASE CHANNELS ON CLOSURE OF SAID COVER ON SAID BASE, SAID BASE CHANNEL WALLS AND SAID COVER CHANNEL WALLS COOPERATING TO SEVER THE INSULATION ABOUT SAID WIRES ON THE CLOSURE OF SAID COVER ON SAID BASE, AN ARM EXTENDING FROM SAID CONNECTOR INTO CONTACT WITH THE WIRES ADJACENT THE CHANNELS ON THE CLOSURE OF SAID COVER, AN INSULATING HOUSING FITTING ABOUT SAID CONNECTOR, SAID HOUSING HAVING WALLS POSITIONED TO ACT ON SAID ARM AND FORCE SAID ARM AGAINST THE WIRES ADJACENT THE SEVERED INSULATION OF COMPRESS SAID WIRES INTO CONTACT WITH THE ELECTRICALLY CONDUCTING WALLS OF SAID BASE, AND MEANS FOR RESTRAINING SAID WIRES IN SAID POSITION. 